PRELIMINARY PIT OUTLINES
In 2007, Golder Associates generated a series of preliminary open pit outlines using Whittle Four-X software (see tables below) based on a 15Mtpa flotation circuit and representative costs for operations of a similar size and nature including mining costs of US$0.85/t, processing and general and administrative costs of US$6.70/t, plus post-concentrator costs. Preliminary metallurgical recoveries were assumed at 85 per cent for copper and silver and 80 per cent for gold for the first case and 85 per cent for copper and 80 per cent for gold and silver for the second case. These assumed values were established from indicative results from metallurgical testing completed to date, which included 42 bulk flotation tests producing a rougher concentrate, as well as the reported results of comparable operations.First pass slope angles of 45 degrees and a mining recovery factor of 95 per cent were assumed, and no allowance was made for mining dilution other than that incorporated in the geological model. Cerro del Gallo Deposit - Resources Contained within Preliminary Pit Shell (Based on Au US$600/oz, Ag US$10.80/oz, Cu US$3.00/lb)
Category Tonnes (M) Au g/t Ag g/t Cu% AuEq g/t AuEq Moz
Measured 59 0.74 13 0.08 1.27 2.4
Indicated 173 0.25 15 0.12 0.96 5.3
Inferred 28 0.21 14 0.12 0.90 0.8
Total 261 0.36 14 0.11 1.02 8.5
3 Moz gold, 117 Moz silver and 632 Mlbs copper
Note: The gold equivalent grade was calculated as Au+(Ag/55.56)+(CuX3.64) and assumes metallurgical recoveries of 80% for gold, and 85% for copper and silver. The conceptual strip ratio is 0.57 and 89% of resources within pit shell are classified as Measured and Indicated. Cerro del Gallo Deposit - Resources Contained within Preliminary Pit Shell (Based on Au US$500/oz, Ag US$9.00/oz, Cu US$1.50/lb)
Category Tonnes (M) Au g/t Ag g/t Cu% AuEq g/t AuEq Moz
Measured 54 0.76 14 0.08 1.18 2.0
Indicated 67 0.29 18 0.13 0.90 2.0
Inferred 4 0.22 17 0.12 0.78 0.1
Total 125 0.49 16 0.11 1.02 4.1
2 Moz gold, 64 Moz silver and 302 Mlbs copper
Note: The gold equivalent grade was calculated as Au+(Ag/55.56)+(CuX2.19) and assumes metallurgical recoveries of 80% for gold and silver, and 85% for copper. The conceptual strip ratio is 0.44 and 97% of resources within pit shell are classified as Measured and Indicated. |